1. Field
Apparatuses and methods consistent with exemplary embodiments relate to authentication structures and methods of authenticating objects, and apparatuses using the authentication structures.
2. Description of the Related Art
A physical unclonable function (PUF) may be used for security purposes. For example, when a PUF is applied to a device (or a product), such as a smart card, a memory stick, a storage medium, or a chip, it may be practically impossible to duplicate the device incorporating the PUF.
A PUF is based on the concept that a slight difference that is caused during a process is used as an identity or identifier of an individual device. Specifically, when light is emitted to a token that is formed by randomly distributing glass beads, a unique pattern is created. Because tokens are generally formed by distributing glass beads, the glass beads are randomly arranged in all of the tokens, and thus it is physically impossible to form the same token. Different patterns are created from tokens, and thus unique identities of the tokens or products including the tokens are established, like human fingerprints. A process of verifying identity, for example using the token or human fingerprint, is referred to as authentication.
However, when authenticating a token that is formed by distributing glass beads, an image unfortunately varies according to a direction in which light is emitted to the token, position of the token, and position of a detector. Also, because the token has a large size, a relatively bulky measurement system is used for authentication. Accordingly, it is difficult to popularize or commercialize authentication using the PUF.